Conventional IP communications service over ATM has been defined by the Internet Engineering Task Force (IETF) in several Request for Comments (RFCs) that describe different ways to encapsulate other protocols in ATM cells. One such RFC is RFC 1483 entitled “Multi-protocol encapsulation over ATM,” which is incorporated by reference herein. Unfortunately, these different types of encapsulation have created a number of options for CPE that attaches to the IP network via a DSL. These options are also referred to herein as “link variants” or simply “variants.” The term “IP communications” as used herein is intended to include any type of IP packets, including IP in an unencapsulated form, or encapsulated in Ethernet, point-to-point protocol (PPP), logical link control (LLC), etc.
Current applications of this technology generally require one of three possible approaches, each of which has significant disadvantages. In the first approach, the customer is required to know the particular variety of IP communications link that is available to them, and to manually configure the corresponding CPE to conform to that link type. For example, the customer may be required to set a particular link mode switch in the CPE. However, this approach is obviously problematic in that it requires a level of technical understanding and ability that customers often lack.
The second approach requires the customer to purchase CPE that is dedicated to a specific link variant. Although this avoids the need for the customer to make adjustments to the CPE, it can present substantial difficulties in situations in which the type of link may change, e.g., if the customer changes Internet Service Provider (ISP). It is clearly undesirable for the customer to be required to replace the CPE in such situations.
The third approach is to have a CPE vendor, or its agent, visit the customer site in person and perform a link configuration operation using conventional administrative techniques. This approach, although it can ensure an accurate configuration, is unduly complex and may be prohibitively expensive for the CPE vendor, network access provider and/or customer.
A need therefore exists for a technique which resolves the issue of link-type determination without the problems associated with the above-described conventional approaches.